Some propellers such as the prop fan, utilize thin swept blades. The shape of the airfoils defining the blades allows high power loading with minimized compressability losses. For instance, the prop fan blades manufactured by the Hamilton Standard Division of the United Technologies Corporation each have a power loading of approximately 37.5 shp/d.sup.2. Such thin swept blades allow a prop fan propeller to achieve a peak efficiency of over 80% at a 0.8 flight Mach number a tip speed of 800 feet per second, and an altitude of 35,000 feet.
The blades must be designed to perform reliably at such high tip speeds and Mach numbers. However, thin, swept blades comprised of, for instance, NACA Series 16 airfoils have several design constraints. The shape of the leading edge of such airfoils makes a blade susceptible to foreign object damage. The shape of the trailing edge makes the blade very difficult to handle. The thin nature of the blade makes the blade difficult to construct.